1. Technical Field
The present invention relates to an electro-optical device, a semiconductor device, a display device, and an electronic apparatus having the same.
2. Related Art
Recently, a technique for reducing power consumption and improving image quality by mounting a light sensor in a display device and measuring illuminance of external light to adjust brightness or the like has been developed (for example, U.S. Pat. No. 5,831,693). Examples of the light sensor include a thin-film transistor, a PIN diode, and a PN diode. It is desirable that a light-receiving unit is a silicon thin film and is manufactured by the same method by which the silicon thin film including a display switching element is manufactured in order not to increase manufacturing cost. At this time, external light refers to all types of environment light, that is, solar light, fluorescent light, incandescent light, LED light, or the like. Appropriate detection of illuminance thereof by use of the light sensor is required.
Solar light has uniform light intensity, but artificial light using AC power supply periodically blinks in many cases. In particular, in a case where glow discharge type fluorescent light is mainly used, the light blinks at 100 Hz or 120 Hz. Moreover, the light sensor is affected by such blinking light, and thus appropriate detection is not achieved.